Method of and apparatus for catalytic treatment of gases



1950 E. B. MILLER 2,507,538

METHOD AND APPARATUS FOR CATALYTIC TREATMENT OF GASES 8 Sheets-Sheet 1 Filed Oct. 14, 1947 May 16, 1950 E. B. MILLER 2,507,538

METHOD AND APPARATUS FOR CATALYTIC TREATMENT OF GASES Filed Oct. 14, 1947 8 Sheets-Sheet 2 //'/1/ l/M A INVENTOR. E. B. Miller BY MfM Artorngys y 1950 E. B. MILLER 2,507,538

METHOD AND APPARATUS FOR CATALYTIC TREATMENT OF GASES Filed Oct. 14, 1947 48 Sheets-Sheet 3 E. El

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METHOD AND APPARA FOR CATALYTIC TREATMENT GASES Filed Oct. 14, 1947 T 8 Sheets-Sheet 4 s U 22 i s9 fi .67; 6| m I J67 65% i I 65 s9- y, -se

May 16, 1950 E. B. MILLER 2,507,538

METHOD AND APPARATUS FOR CATALYTIC TREATMENT OF GASES Filed Oct. 14, 1947 8 Sheets-Sheet 5 8| kss H p L 8| /////4 w 80 /70 y m: I I 75 7? 82 78 7s 83 IN KEN TOR.

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METHOD AND APPARATUS FOR CATALYTIC TREATMENT OF GASES Filed 001;. 14, 1947 a Sheets-Sheet 6 92 r T 90 U x 9| e5 1 INVENTOR. 'E.B. Miller Z BY Z 2 963 Attorneys May 16, 1950 E. B. MILLER METHOD AND APPARATUSFOR CATALYTIC TREATMENT OF GASES Filed Oct. 14, 1947 r 8 Sheets-Sheet '7 1 INVENTOR. EB. Miller v Aitorneys May 16, 1950 E. B. MILLER 2,507,538

METHOD AND APPARATUS FOR CATALYTIC v TREATMENT OF GASES Filed on. 14, 1947 8 sheets-sheet 8 95045 Y uogmmav'i Jawa PJULL E9 J' Jawa afimg puooag 4 J Ta na 4s Wu J .nama j INVENTOR. E. B. Miller BY E Attorney;;

Patented May 16, 1950 UNIED STATES Ernest B. Miller, Houston, Tex.

Application October 14, 1947, Serial No. 779,825

3 Claims. 1

This invention relates to catalyzing gaseous reactions and has more particular reference to a method of and apparatus for catalytic cracking of hydrocarbon vapors and the like.

One object of the present invention is to provide a novel method of and apparatus for catalytic cracking of hydrocarbon vapors and the like to produce lighter hydrocarbons.

Another object of the invention is to provide a converter in which a plurality of catalyzing units are successively moved into and through one or more reaction chambers and then into and through an activation chamber in which they are prepared for a repetition of the cycle.

Another object of the invention is to provide a converter as characterized above wherein the reaction and activation chambers are mounted within a pressure vessel to permit equalization of pressures within and without the chambers.

Another object of the invention is to provide a converter in which a large surface area of relatively thin layers of granular catalytic material, offering a minimum of resistance to the flow of gases, is condensed into a small cubic space.

Another object of the invention is to provide a system for catalytic cracking of vapors including a converter as characterized above, wherein means are provided for controlling the temperature of the vapors to be cracked during their passage through the converter.

Another object of the invention is to provide a system for catalytic cracking or" vapors as characterized above, wherein means are provided for continuously heating and re-circulating a regenerating medium through the activation chamber of the converter.

Other objects and advantagesof the invention will appear in the specification, when considered in connection with the accompanying drawings, in which:

Fig. 1 is a side elevation showing the mounting and arrangement of the apparatus of the invention, but omitting the converter driving mecha- ,nism;

Fig. 2 is a plan View of the apparatus shown in Fig. 1;

Fig. 3 is a plan View of the converter;

Fig. 4 is a side elevation, partly in section, of the converter driving mechanism;

Fig. 5 is a vertical sectional view of the converter, taken on line 5-5 of Fig. 3, but omitting the driving mechanism;

Fig. 6 is a horizontal sectional View of the corn verter, taken on line 66 of Fig. 5, but drawn to a smaller scale;

- manifold, showing the details of a roller;

Fig. 12 is a plan view of a tubular catalyst containing unit;

Fig. 13 is a vertical sectional View, with part broken away, taken on line -l3l3 of Fig. 12; and

Fig. 14: is a diagrammatic view showing the flow of vapor to be cracked and the flow of the regenerating medium through the system.

In general, the invention comprises a method of and apparatus for continuously directing the flow of the vapor to be treated into and through one or more reaction chambers, heating the vapor to a. predetermined temperature prior to its passage into each reaction chamber; continuously heating and directing the flow of a regenerating medium into and through an activation chamber; and continuously and successively moving a plurality of catalyzing units into and through the chambers.

For purposes of illustration, the invention will be described in connection with the catalytic treatment of hydrocarbon vapors to produce lighter hydrocarbons, for example, a vaporized gas oil. Gas oil is one of the fractions derived from topping crude oil, and, prior to being treated, is vaporized at about 15 ibs. pressure in the usual manner, which forms no part of this invention.

Referring now to the drawings, there is shown, in Figs. 1 and 2, one embodiment of apparatus and the arrangement thereof for carrying out the method of this invention. Th apparatus shown includes a four-stage converter i, three stages of which are used as reaction chambers in which the vapor is brought into intimate contact with the catalyst, the fourth stage is used as an activation chamber in which th catalyst is regenerated; a heater for the vapor prior to its passage through the reaction stage; a second heater 3 for heat.

the vapor (5 between the first and second reaction stages; a third heater 3 for heating the Vapor oetr second and third reaction stages;

a raised position by a suitable framework, indicated at 6.

The vapor to be treated is delivered from a source of supply (not shown) to the first reaction stage heater 2 by means of a pipe line 1'. The vapor is heated in the heater to from 850 F. to 900 F., and then passes through pipe line 5 to the first reaction stage of the converter. During its passage through the first stage of the converter the hot vapor is brought into intimate contact with the catalyst and partially cracked. After passing through the first stage of the converter, the partially cracked vapor passes through pipe line 9 to the second reaction stage heater 3, where it is heated to from 900 F. to 950 F. From the second stage heater 3, the heated, partially cracked vapor passes through pipe line it} to the second reaction stage of the converter. During its passage through the second stage, the hot partially cracked vapor is brought into intimate contact with the catalyst and further cracking takes place. After passing through the second stage of the converter, the vapor passes through pipe line H to the third reaction stage heater 4, where it is heated to from 950 F. to 1000 F. From the third stage heater 4, the heated vapor passes through pipe line I2 to the third reaction stage of the converter. During its passage through the third stage the hot partially cracked vapor is brought into intimate contact with the catalyst and the final cracking takes place. After passing through the third stage, the completely cracked vapor is delivered through pipe line l3 to the usual condensing and fractionating equipment (not shown).

29 suitably journalled in bearings carried by the upper and lower shell members 25, 26. The mechanism for rotating the annular drum is supported on a platform 30 mounted on the upper shell 25 and includes a shaft 3| connected to the upper end of the shaft 29 by a coupling 32. The shaft 3| is driven by suitable reduction gearing mounted in a housing 33, the reduction gearing being belt-driven by a motor 34.

The rotatable annular drum 24 comprises two spaced concentric cylinders 35, 36 which form the side walls; two spaced annular plates 31, 38, each secured to the top of the cylinders 35, 36, respectively form the top of the drum, the space between the annular plates 31, 38 forming an annular opening 39 in the top of the drum; two spaced concentric annular plates 40, 4|, each secured to the bottom of the cylinder 35, 36, respectively form the bottom of the drum, the space between the annular plates 45, 4 I, forming an annular openin 42 in the bottom of the drum.

The rotatable annular drum is divided into a plurality of compartments 43 by radial partitions or diaphragms 44. In each of the radial compartments 43, near the bottom thereof, there is provided a plate 45 attached to the walls of the compartment, as by welding, to form a gastight joint. Each plate 45 forms a support for one or more tubular catalyst containers 46. In the particular embodiment shown, only one such container is shown mounted in each compartment.

The catalyst containers 46 are identical in construction and, as best shown in Figs. 12 and 13,

each comprises two concentric tubular wire The regeneratin medium, preferably air, is I supplied to the regenerating medium heater 5, where it is heated to from 1000 F. to 1200 F., and from the heater passes to the activation stage of the converter through pipe line I4. During its passage through the activation stage the heated air is brought into intimate contact with the catalyst and burns off the carbon from the catalyst and restores or regenerates it for reuse. From the activation stage, the hot air passes through pipe line l5 to a conduit it, from which it is either discharged to the atmosphere or is recirculated through the heater 5. One end of the conduit I6 is connected to the inlet of a fan or blower ll and the other end opens to the atmosphere. The conduit It also has connected thereto a second conduit [8, which is open to the atmosphere. Valves I9 and 20, located in the conduits I6 and I8, respectively, permit partial recirculation of the heated air through the heater and activation stage of the converter as a means of economizing heat. The converter is similar in construction to the dehydrator shown in my co-pending application Ser. No. 706,108, filed October 28, 1946, for Method of and apparatus for dehydrating gas and recovering condensable hydrocarbons therefrom, and comprises a pressure vessel 2|; upper and lower annular manifolds 22, 23, fixedly mounted within the vessel; a compartmentized annular drum 24 rotatably mounted within the pressure vessel between and in communication with the manifolds; and suitable driving mechanism for rotating the annular drum.

The pressure vessel 2| is preferably formed in two parts, an upper flanged shell or cap 25 and a lower flanged shell 26 suitably secured together, as by bolting, to form a gas-tight joint.

The annular drum 24 is fixedly attached, as by means of plates 21, 28, to a central vertical shaft screens 47, 48 held in spaced relation by a plurality of longitudinal radial fins 49, with the annular space between the screens closed at the bottom. The mesh of the screens is such as to retain a granular catalyst material 50 in the annular space between the screens. Although the invention is not limited thereto, it is preferred to employ a catalyst wherein granular silica gel or a substance having substantially the same structure is the carrier for the active material, preferably aluminum oxide.

Each of the containers 46 is closed at its top by means of concentric hoops 5|, 52 mounted on the concentric screens 47, 48, and a cover plate 53 detachably connected to the inner hoop 52, as by screw bolts, and having 0. depending annular flange 54 fitting between the hoops 5|, 52. A depending annular fin 55 is secured to the flange 54 and projects downwardly between and .1. below the hoops 5|, 52, and fits in slots 56 formed in the upper ends of the radial fins 49, all as shown in Fig. 13. The construction being such that, as the catalyst settles down, leaving a space between the top portion of the wire screens devoid of catalyst, the fin 55 will prevent gas or vapor from passing through the space devoid of catalyst. Each container is detachably mounted on a nozzle 5? projecting upwardly from an opening 58 formed in the plate 45, as clearly shown in Fig. 5. The nozzle 5'! is secured in the opening 58, as by welding, to form a gas-tight joint.

The top and bottom manifolds 22, 23 are mounted on the top and bottom of the annular drum 24, in communication with the annular openings 39, 42 formed in the top and bottom of the drum. The manifolds are identical in construction and each is formed in the shape of an annular through having an annular top 5 r atten.) and mesh: side. Wa s 6 we? P e. 7

A ur it of impress on s rin s. 62.. m nt d o a k t su a l secur d t the. nner walls f the vesse 2 yieldab r r ss the ten and b t m mani ol s ainst he ten and bottom. respectively, of the annular drum, as shown in s- 5- 'E ae ta bott m. mani olds ar h ld ta onar re ative e rotation f. t e annular rum by m an ereinit r to. e, de cr be and. to pr ven the sc p o sashetween t e rota in drum and the manifolds, sealing ring gaskets 6d. are placed at the junction of the side walls of the ma old and the drum. The sealing ring gaskets are held in tight sealing engagement with the p and bo tom. o he drum by means of annular hoops, i which, encircle,v the baskets and hold them against, the side walls of the manifold, as shown in Fig. 7,. The upper (or lower) ends of the hoops. are secured to the top (or bottom) plate of the manifold, as by welding. The ring gaskets are retained between the hoops S5 and the side walls fill, iii of the manifolds by means of a plurality of circumferentially spaced threaded bolts 655, which engage, the ring gasketsw and the. lower portions of the hoops and side walls. The ring gaskets as are, yieldably held in engagement with. the top and bottom of the drum 2d by means of a p1urality of compressed springs 61 mounted on stud bolts 62, secured to the. top, (or bottom). of. the manifolds and engaging annular plates or members as mounted on the top (or bottom) of the ring gaskets, all as clearly shown in Fig. 7.

At four circumferentially spaced points in the top and bottom manifolds, there are located seals which, by reason of the sliding contact, of the radial partitions against the under surface of. the bottoms of theseals, divide the manifolds and d um into four sectors, each sector gas ,-tight, wi a respect to the adjacentseotors, The seals are ti al n ns r ction and. he ailsv thereof are best shown in Figs. 7, Sand-9. Each seal includes a bottom or sealing plate lb mounted within the manifold betweenspacedradial partition walls ii, it. The bottom plate l9 ieyieldably urged against the top (or bottom) of the v drum and rests on the; concentric annular plates 3'6, 38 which form the top of;the,dru n (or plates at, 3! which form the. bottom of the drum), as shown in Fig. 7. bifurcated, as shown at '53, 'i for the; receptionof gasket l5, l5, whichareyieldably pressed outwardly against the partitionwalls ll, 12 of;

the seal by leaf springs 1?, i8, asshown in Figs. 8 and 9.

They means for yieldingly pressing the bottom plate. '16 of the seal against the top (or-bottom) of the drum comprisea plurality of compressionsprings '55 mounted on projections 88, formed on theupper surface of the plate 10. The springs l3 engage the top (or bottom) of the seal-and are held in position byboltsill proj ectingthrough the top (or bottom) of the sealand thecoiled springs and threaded into the projections 88 formed on theplate l0.

Each radialpartitionor diaphragm M has a;.

portion of its top andbottomedges extending upwardly (ordownwardly) between theedgesof,

PlatesjB; are secured to, the; tops :and; bottoms The side edges of v, the; plateare oi the partitions and. are held spaced therefrom by a spacer strip es, the plates and spacer strip being secured to the partitions by bolts 85. The gaskets, 82 are confined between the partitions and the. plates 233, as by means of bolts 86, and are pressed upwardly (or downwardly) against the under surface of the bottom plates 79 of the seals by means of leaf springs 8'5, all as shown in Fig. 9.

In order to prevent the gaskets 82 from being unduly pressed upwardly (or downwardly) when the gaskets are not engaging the bottoms of the seals, meansv are provided for spanning the reaches of the manifolds between the seals.

* These means comprise spaced pairs of curved plates. 8, 89, which extend between and are secured, to the partition walls of the seal, as shown in Fig. 1.0. The. bottom. surfaces of the plates 89. are in the same horizontal plane as the bottom surfaces of the bottom plates it of, the seals, so. that, as the, gaskets move out of engagement with the bottom plate of the seal, they immediately engage the plates 38., 89

A plurality ofrollers are mounted within the top bottom manifolds. These rollers are circumi'erentialiy spaced within the manifolds and are adapted to engage the. plates 3?, which form parts. of the top. and bottom, respectively,cf tb rotatable drum.v These rollers are adaptedto ev nt frictional surface engagement betweentn side walls of the manifolds. and the top bottom of the, drum. These rollers are identical in construction, and, moantingv and. each comprises a threaded studbolt ill screwed into the outer sidewall d5. of the manifold; a ball race iitgnxedly mounted on, the bolt, and a wheel 93 mounted on the ball race, all. as shown in.

Fou pipes; or conduits 5, as, and: a? hav ing threaded; ends project through the cap. or. the vessel 2| and have their threaded ends iscured to the; top plate of the top manifold by means of loch-nuts Q3, which form. gas-tight joints. the top manifold stationary relative to the. rotation; of the drum. The four; pipes are. circumferentially spacedrwith respect tothe top. manifold; and-; e,acl1.-is secured to and communicates withthe manifold ata point locatedbetween the seals.

Four additional pipes 99, its, Hill an its, havingthreaded ends, project through the bottom of thevessel 2i and havet'heir'threaded ends secured-to the bottomplate of the bottom manifold by means oilock nuts loft-which form gas-tight These pipes are welded to thebottom of.

joints. the vessel 29. and hold the bottom manifold stationary; relative to the rotation of, the drum. These pipes are ci-rcumferentially spaced with respect to the bottom manifold and each is socured toand communicates with the manifold at a point located between the seals. The'widthof the seals withrespectto the radial compartments 33 containing the catalyzing unitsis such that at all times, at least one ofthe partitions or diaphragmss l-is engaging the bottom; plate is of thesealingas-tight engagement. From the foregoing, it will readily be seenthat by the engagement of the radial partitions with the seals, the manifoldv anddrum are. divided into four gastight-chambers or sectorswhich form. the first, second; and third reaction stages and the activation stages... catalyst containers is-rotated counter-clockwise as.=.viewed inaFig; 2, and, as it rotates, the: til--- Thepipes arewelded to. thecap and hold.

Thedrum ii' lcarrying the tubular bular catalyst containers are successively moved through the four sectors or stages in the following order: the activation stage, the third reaction stage, the second reaction stage and the first reaction stage. The four pipes 94, 95, 96 and 9'5 are connected to pipe lines 8, i0, i2 and 15, respectively; and the four pipes 99, I00, NH and 192 are connected to pipe lines 9, H, l3 and I4, respectively, by means of which the vapor and hot air flow into and through the converter.

The flow of the vapor through the reaction stages and the flow of the hot air through the activation stage are shown schematically in Fig. 14.

The vapor to be cracked, after being heated to i the optimum cracking temperature in the first reaction stage heater, passes through pipe line 8 to the converter and enters the top manifold of the first stage through pipe 94. Then it moves downwardly from the manifold and through the opening in the top of the drum into the various compartments of the drum containing the catalyst containers, as are at that time contained within the sector forming the first reaction stage. The vapor passes through the pervious layer of catalytic material into the interior of the tubular containers, thence downwardly through the openings in the plates 5 into the bottom of the drum and through the opening therein into the bottom manifold. From the bottom manifold the now partially cracked vapor passes through pipes 99 and 9 to the second reaction stage heater where the temperature of the vapor is again raised to the optimum cracking temperature. From the second reaction stage heater, the vapor passes through pipes to and 95 into the top manifold of the second reaction stage. lhe vapor moves downward through the second reaction stage, in a manner similar to its downward movement through the first reaction stage and during its passage further cracking takes place. After passing through the second reaction stage, the vapor passes through pipes 599 and i I to the third reaction stage heater 6 where the temperature of the vapor is again raised to optimum cracking temperature. From the third reaction stage heater the vapor passes through pipes I2 and 96 into the top manifold of the third reaction stage. The vapor moves downwardly through the third reaction stage in a similar manne to its downward movement through the other reaction stages and, during its passage, the final cracking takes place. After passing through the third reaction stage, the vapor passes through pipes l9! and [3 to the condensing and fractionating apparatus (not shown).

The burning off of carbon and the removal of other impurities from the catalytic material is effected in the activation stage. The regenerating medium, preferably air, is pumped, by means in the plates 45 and up into the interior of the tubular catalyst container, through the pervious layer of catalyst material in the compartments of the drum. As the hot air passes through the catalyst material, the carbon formed thereon is burned off and other impurities are removed.

The hot air then passes through the opening in the top of the drum into the top manifold. From the top manifold, the hot air passes through pipes 91 and. i5 into the conduit 1'6 from which it is exhausted to the atmosphere. If desired, in order to conserve heat, a portion of the hot air discharged into conduit l6 may be recirculated through the regenerating medium heater and the activation stage. By mounting the annular drum and the manifolds within a pressure vessel, the method may be carried out with high pressure gases and, too, the equalization of pressure within the drum, manifolds and vessel permit the drum and manifolds to be made of lighter weight material, which adds considerably to the efficient and economical operation of the converter. This equalization of pressure is accomplished by means of a small opening formed in that portion of the pipe line 94 within the vessel 2 l. And too, due to the unequal temperature of the gas as it passes through the various sectors, thereby resulting in unequal expansion of the parts of the drum and manifolds, it is considered desirable to provide each of the eight pipes 94, 95, 9S, 9?, 99, iEIG, HH' and I02 with expansion joints 94 located a short distance from their points of connection to the manifolds.

From the foregoing, it will be seen that there has been provided a novel method of and improved apparatus for catalytic cracking of petroleum vapors. The method comprises, broadly, the steps of continuously circulating a catalytic material in a closed path; continuously heating and directing the flow of the vapor to be cracked through the catalytic material at one or more points in its closed path; and continuously heating and directing the flow of a regenerating medium through the catalytic material at another point in its closed path to regenerate the catalyst.

At this point, it may be well to point out that the vapor to be cracked flows through the catalyst in the same direction in all the reaction stages, viz., from the outside to the inside of the tubular containers, while the regenerating medium flows through the catalyst in the opposite direction in the activation stage, viz., from the inside to the outside of the tubular containers. This reversal of flow, as it were, has an important bearing in the practice of the method of the invention. In the reaction stages, due to the flow from outside to inside of the tubular containers, the reaction progressively decreases from the outside to the inside, which results in a heavier deposit of carbon, and other impurities, on the catalytic material adjacent to the outer circumference of the tubular containers. Accordingly, by reversing the flow of the regenerating medium, in the instant case, hot air, the deposited carbon and other impurities are more quickly and efficiently removed.

While the invention has been described in connection with the cracking of vapors obtained from gas oils, obviously, it is also applicable to other catalytic reactions in which vapors are subjected to the action of a suitable solid catalyst. such as hydro-forming, reforming, and the like. For example, it may be employed in hydro-forming ordinary gasoline to produce gasoline of a higher octane value for use as motor fuel. In that case, the range of temperatures and pressures will be changed to suit the particular conditions under which the system is operated. For hydro-forming, the temperature ranges will be around from 900 F. to 1000 F., while the pressure will be from 10 to 50 pounds per square inch. An ordinary molybdenum catalystflviooc about may be efiectively employed in this process. It will be activated with air or any suitable source of oxygen. The time required for the completion of the cycle will be about the same (ten minutes or more).

Obviously, the invention is not restricted to the particular embodiments thereof herein shown and described. Moreover, it is not indispensable that all "of the features 01 the invention be used conjointly, since they may be employed advantageously in various combinations and subcombinations.

What-is claimed is:

1. In :the catalytic cracking of hydrocarbons involving the contact of a catalyst with vaporized hydrocarbons with resultant-deposition of carbon on the catalyst and the "subsequent treatment of the catalyst in an oi-ridizing atmosphere to burn the carbon and regenerate the catalyst for further contact with the hydrocarbons, the improvement which comprises rotating a series of separated thin-beds of catalyst directly in succession and substantially continuously relative to and through a reaction zone and a regenerative zone; continuously directing the flow of the vaporized hydrocarbons through said reaction zone; heating the vaporized hydrocarbons to an optimum reaction temperature prior to their passage throughthe reaction zone; continuously withdrawing the cracked hydrocarbons from the reaction zone; and continuously directing the flow of a hot oxidizing medium through the regencrating zone to burn the residual gas in the beds therein and also to oxidize the carbon on the catalyst; and continuously withdrawing the resulting carbonaceous gases from said regenerating zone.

2. In the catalytic cracking of hydrocarbons involving the contact of acatalyst with vaporized hydrocarbons with resultant deposition of carbon on the catalyst and the subsequent treatment of the catalyst in an oxidizing atmosphere to burn the carbon and regenerate the catalyst for further contact with the hydrocarbons, the improvement which comprises rotating a series of separated thin beds of catalyst directly in succession and substantially continuously relative to and through a succession of reaction zones and a regenerating zone; continuously directing the flow of the vaporized hydrocarbons in succession and in series through said reaction zones; heating the vaporized hydrocarbons to an optimum reaction temperature prior to their passage through each of the reaction zones; continuously withdrawing the cracked vaporized hydrocarbons irom the last one of the reaction zones; continuously directing the flow of a hot oxidizing medium through the regenerating zone to burn the residual gas in the beds therein and also to oxidize the carbon on'the catalyst; and continuously withdrawingthe resulting carbonaceous gases from said regenerat ing zone.

3. The method, as set forth in claim 2, wherein the direction of the series flow of the vaporized hydrocarbons is opposite to the direction of rotation of the catalyst beds, whereby the vaporized hydrocarbons will always make their last passage through freshly generated catalyst beds.

ERNEST B. MILLER.

REFERENCES GI-TED The following references are of record in the. file of this patent:

UNITED STATES PATENTS Number Name Date 2,236,138 Howard Mar. 25, 1941 2,246,654 Arveson June 24, 1941 2,304,398 Campbell Dec. 8, 1942 2,310,244 Lassiat Feb. 9, 1943' 2,317,379 Hemminger Apr. 27, 1943 2,347,829 Karlsson et a1, May 2, 19 14, 

1. IN THE CATALYTIC CRACKING OF HYDROCARBONS INVOLVING THE CONTACT OF A CATALYST WITH VAPORIZED HYDROCARBONS WITH RESULTANT DEPOSITION OF CARBON ON THE CATALYST AND THE SUBSEQUENT TREATMENT OF THE CATALYST IN AN OXIDIZING ATMOSPHERE TO BURN THE CARBON AND REGENERATE THE CATALYST FOR FURTHER CONTACT WITH THE HYDROCARBONS, THE IMPROVEMENT WHICH COMPRISES ROTATING A SERIES OF SEPARATED THIN BEDS OF CATALYST DIRECTLY IN SUCCESSION AND SUBSTANTIALLY CONTINUOUSLY RELATIVE TO AND THROUGH A REACTION ZONE AND A REGENERATIVE ZONE; CONTINUOUSLY DIRECTING THE FLOW OF THE VAPORIZED HYDROCARBONS THROUGH SAID REACTION ZONE; HEATING THE VAPORIZED HYDROCARBONS TO AN OPTIMUM REACTION TEMPERATURE PRIOR TO THEIR PASSAGE THROUGH THE REACTION ZONE; CONTINUOUSLY WITHDRAWING THE CRACKED HYDROCARBONS FROM THE REACTION ZONE; AND CONTINUOUSLY DIRECTING THE FLOW OF A HOT OXIDIZING MEDIUM THROUGH THE REGENERATING ZONE TO BURN THE RESIDUAL GAS IN THE BEDS THEREIN AND ALSO TO OXIDE THE CARBON ON THE CATALYST; AND CONTINUOUSLY WITHDRAWING THE RESULTING CARBONACEOUS GASES FROM SAID REGENERATING ZONE. 